Houston flood: How much is 9 trillion gallons of water?

Houston and Southwest Texas are drowning in what the National Weather Service estimates to be 9 trillion gallons of rainwater—so far [as of two days into the disaster]. From a distance, and from the high, privileged ground on which I live, it is hard to visualize how widespread the flooding is—even if you watch the endless hours of live tv coverage featuring images shot from drones and helicopters. It’s even harder to conceptualize what 9 trillion gallons of water is.

If that water were collected into a cube next to Houston’s downtown, it would be approximately four miles square and two miles tall.

9 trillion gallons of water is enough to fill the entire Great Salt Lake twice.

It would take 9 days straight for the Mississippi River to drain into Houston and equal the amount of water already there.

If we averaged this amount of water spread equally over the lower 48 states, that’s the equivalent of about 0.17 inches of rain—roughly the height of three pennies stacked atop each other—occupying every square inch of the United States.

This amount of water could fill 2.3 percent of the volume of the mountain range containing Mount Everest.

9 trillion gallons is enough to fill 33,906 Empire State Buildings from basement to penthouse.

If we took the amount of rainfall that Texas has seen [so far], and spread it over the city limits of New Orleans, it would tower to 128 feet in height—roughly reaching as high as a 12-story office building.